The present invention relates to the field of acoustical insulation and, more particularly, to acoustical insulation with an integral water barrier.
Acoustical insulation is well known in the art. Acoustical insulation typically relies upon both sound absorption, i.e. the ability to absorb incident sound waves, and transmission loss, i.e. the ability to reflect incident sound waves, in order to provide sound attenuation. One of the more prevalent uses of such insulation is in the motorized vehicle field where engine compartments, fire walls, fender wells, doors, floor panels and other components of the passenger compartment shell are commonly acoustically insulated to reduce engine and road noise for the benefit and comfort of passengers.
Examples of acoustical insulation commonly employed for vehicle applications are found in U.S. Pat. Nos. 5,298,694 to Thompson et al., 5,624,726 to Sanocki et al., 5,759,659 to Sanocki et al. and 5,961,904 to Swan et al.
The 5,298,694 patent discloses a non-woven acoustical insulation web of thermoplastic fibers and a second layer, such as a scrim, non-woven fabric, film or foil, laminated thereto for water barrier protection.
The 5,624,726 and 5,759,659 patents disclose an acoustical insulation blanket in the form of a composite featuring an insulation layer of fibrous insulation, foam insulation or a combination thereof and a high temperature-resistant layer of ceramic paper, woven ceramic fibers, woven fiberglass fibers, ceramic non-woven scrims or fiberglass non-woven scrims encased in a heat sealable thermoplastic polyolefin which functions as a moisture barrier.
The 5,961,904 patent discloses a non-woven acoustical insulation web of thermally stabilizing melt-blown polypropylene microfibers which may also contain staple fibers such as crimped bulking fibers and/or binder fibers. The acoustical insulation web is formed as a laminate with a water barrier layer of planer thermoplastic polyolefin film such as polyethylene, polypropylene and ethylene-propylene copolymer films.
In many acoustical insulation applications and particularly those relating to motorized vehicles, water barrier protection is an important concern. As demonstrated by these prior art patents it has generally been found necessary to add water barrier protection to the acoustical insulation material which is pervious to water and may allow water intrusion into the vehicle passenger compartment. Typically it has been necessary to provide laminate constructions which are effective for the intended purpose but suffer several shortcomings. Specifically, delamination may occur as a result of handling and manipulation during installation or various environmental factors. Delamination typically reduces the effectiveness of the water barrier thereby potentially allowing for unwanted water intrusion into the interior of the vehicle. A need is therefore identified for an improved acoustical insulation providing dependable water barrier protection over an extended service life.
In accordance with the purposes of the present invention as described herein, an acoustical liner with integral water barrier is provided. The acoustical liner is formed with a pad of fibrous material having a lofty, acoustically insulating material having at least one heat-seared, water-barrier face. The fibrous material preferably has a density of between about 0.6-4.0 lbs/ft3 with the heat sealed face having a thickness of between about 0.01 and 5.0 mils. The pad may be formed from fibrous materials such as polyester, fiberglass, polypropylene and any mixtures thereof or other suitable fibers. The pad and heat-seared, water-barrier face are integral and, accordingly, the acoustical liner is a non-laminate. As such, it avoids the tendency to delaminate which is characteristic of the water barrier layers laminated to acoustical insulation materials of the prior art.
The acoustical liner with integral water barrier may further include a crimped margin around at least a portion of the periphery of the pad where the crimped margin has a thickness of at least about 0.5-3.0 mm. This margin provides additional strength and a suitable location to mount the liner to a structural component of a vehicle, such as a door panel, which requires acoustical insulation with water barrier protection, by known fasteners.
The pad of the acoustical liner with integral water barrier may also include two heat-seared faces.
In accordance with yet another aspect of the present invention a method of insulating a door including an exterior body panel and an interior fascia panel defining a cavity therebetween is provided. The method comprises the placing of a pad of fibrous material in the cavity between the exterior body panel and the interior fascia panel. The pad has a lofty, acoustically insulating portion having a density of between about 0.6 and 4.0 lbs/ft3 and at least one heat-seared face having a density of between about 0.01 and 5.0 mils.
In accordance with yet another aspect of the present invention a door for a vehicle is provided. The door includes an exterior body panel, an interior fascia panel connected to the exterior body panel and defining a cavity therebetween and a pad of fibrous material having a lofty, acoustically insulating portion having a density of between about 0.6 and 4.0 lbs/ft3 and at least one heat-seared, water-barrier face having a thickness of between about 0.01 and 5.0 mils. The pad may be formed from fibrous materials selected from a group consisting of polyester, fiberglass, polypropylene and any mixtures thereof. The pad is not a laminate and may also include a crimped margin around at least a portion of the periphery of the pad where the crimped margin has a thickness of between about 0.5 and 3.0 mm. As noted above, this crimped margin provides a convenient fastening point for securing the acoustical liner to the exterior and/or interior panels of the component to which the acoustical liner is to be secured. The pad of the acoustical liner may also include two heat-seared faces. Of course, the door may also include a window.
Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described embodiments of this invention, simply by way of illustration of two modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.